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"Indonesia is expected to apply the strategy of long term storage for spent fuel generated from the Serpongresearch reactor. The capacity of existing interim storage for spent fuel (ISSF) facility in principle able toaccommodate all the spent fuel generated Serpong research reactor, but it must consider long-term conditions ofthe spent fuels and the wet storage facilities. This long-term strategy requires special attention to someparameters dealing with the water chemsitry and the degradation of the materials. Besides it is necessary to builtreserve space to deal with emergencies. After the Serpong reactor decommissioned, it is recommended to buildthe new dry storage to accomodate all of the spent fuel in another location since the Serpong area will be verydense residential in the decades to come. The most realistic future back-end scenario is if Indonesia has nuclearpower plants (NPP), then the disposal of the spent fuel generated from research reactor in the future can be donein one location with commercial spent fuel from the NPP."

"This study proposes a method of optimizing the dry storage design for nuclear-spent fuel from the G.A. Siwabessy research reactor at National Nuclear Energy Agency of Indonesia (BATAN). After several years in a spent fuel pool storage (wet storage), nuclear spent fuel is often moved to dry storage. Some advantages of dry storage compared with wet storage are that there is no generation of liquid waste, no need for a complex and expensive purification system, less corrosion concerns and that dry storage is easier to transport if in the future the storage needs to be sent to the another repository or to the final disposal. In both wet and dry storage, the decay heat of spent fuel must be cooled to a safe temperature to prevent cracking of the spent fuel cladding from where hazardous radioactive nuclides could be released and harm humans and the environment. Three optimization scenarios including the thermal safety single-objective, the economic single-objective and the multi-objective optimizations are obtained. The optimum values of temperature and cost for three optimization scenarios are 317.8K (44.7°C) and 11638.1 US$ for the optimized single-objective thermal safety method, 337.1K (64.0°C) and 6345.2 US$ for the optimized single-objective cost method and 325.1K (52.0°C) and 8037.4 US$ for the optimized multi-objective method, respectively."

"Penelitian ini bertujuan untuk memberikan solusi penyimpanan Bahan Bakar Nuklir Bekas (SNF) di Indonesia. Karena keterbatasan ruang pada penyimpanan tipe basah, maka penelitian ini merancang, mensimulasikan, melakukan eksperimen, dan menghitung biaya pembuatan penyimpanan dry cask storage secara simultan. Dalam studi ini, desain dry cask storage dioptimalkan dengan menggunakan dua objective functions secara bersamaan yaitu fungsi keselamatan (yang menggabungkan parameter kekritisan, proteksi radiasi dan penghilangan panas) dan fungsi biaya. Perhitungan optimasi kemudian divalidasi dan dianalisis dengan data eksperimen dari prototipe dry cask storage. Dengan menentukan decision variables dan constraints, kemudian memasukkannya ke dalam Matlab software, diperoleh tiga pilihan hasil optimasi, safety optimized, cost optimized dan multi-objective optimized. Dalam multi-objective optimized, desain penyimpanan kering yang optimal diperoleh untuk radius luar beton dan timbal (Pb) masing-masing sebesar 0,06 m dan 0,51 m. tinggi ventilasi dan lebar masing-masing sebesar 0,15 m dan 0,5 m, dan perbedaan ketinggian ventilasi sebesar 2,43 m. Untuk kelima variabel diatas, nilai optimum temperatur permukaan kanister adalah 66,8 °C dan biaya yang dibutuhkan untuk pembuatan dry cask storage adalah $147,827. Ketebalan material yang dibutuhkan didapatkan nilai yang paling optimum untuk Pb 0,06 m dan beton 0,51 m, dari validasi menggunakan MicroShield software didapatkan paparan permukaan penyimpanan dry cask sebesar 104,8 mR/jam sehingga masih dalam batas aman dari nilai maksimum yang ditentukan yaitu 160 mR/jam. Demikian pula dari simulasi suhu permukaan tabung menggunakan Ansys Fluent software untuk kelima variabel di atas, nilai suhu permukaan mendekati perhitungan yang persamaannya dimasukkan ke dalam Matlab software. Validasi menggunakan data eksperimen dari prototipe dry cask storage dan juga perhitungan manual diperoleh nilai temperatur yang juga relatif mendekati hasil optimasi, yaitu 45,2 °C untuk temperatur dari eksperimen dan 50.2 °C untuk temperatur perhitungan teori. Hasil nilai optimasi terpilih dengan tetap menjaga keamanan termal menunjukkan bahwa acuan dalam pembuatan desain dengan skala 1:1 dapat menggunakan estimasi untuk keamanan termal T1, untuk jenis SNF Materials Testing Reactor (MTR) dengan umur setelah sepuluh tahun disimpan pada jenis penyimpanan tipe basah.

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This research aims to provide a solution for Indonesia's spent nuclear fuel (SNF) storage. Due to the limited storage space in wet type storage, this research designs, simulates, conducts experiments, and calculates the cost of making dry cask storage simultaneously. In this study, the dry storage design was optimized by using two objective functions simultaneously: safety function (which combines criticality parameters, radiation protection and heat removal) and cost function. The optimization calculations were then validated and analyzed with experimental data from the dry cask storage prototype. By determining the decision variables and constraints and then inputting them into the Matlab software, three choices of optimization results are obtained, safety optimized, cost optimized and multi-objective optimized. In multi-objective optimized, the optimum dry storage design is obtained for the concrete outer- and lead (Pb) outer-radius of 0.06 m and 0.51 m respectively. vent-height, -widt by 0.15 m and 0.5 m respectively, and a vent elevation difference of 2.43 m. For the five variables above, the optimum value for the canister surface temperature is 66.8 °C and the cost required to make dry storage is $ 147,827.The required thickness of the material obtained the most optimum value for Pb 0.06 m and concrete 0.51 m, from validation using MicroShield software, it was obtained that the dry cask storage surface exposure was 104.8 mR/h so that it is still within the safe limit of the maximum value specified, which is 160 mR/h. Similarly, from the simulation of canister surface temperature using Ansys Fluent for the five variables above, the surface temperature value is close to the calculation whose equations are inputted into matlab. Validation using experimental data from the dry storage prototype and also manual calculations obtained temperature values which are also relatively close to the optimization results, 45.2 °C for temperature from experiments and 50.2 °C for temperature from manual calculations. The result of the selected optimization value while maintaining thermal safety indicates that reference in making designs with a scale of 1:1 can use the estimate for the thermal safety of T1, for the type of SNF Materials Testing Reactor with age after ten years stored in the wet storage type."

"Untuk meningkatkan keselamatan termal pada saat terjadi kecelakaan akibat station blackout, vertical straight wickless-heat pipe pipa kalor lurus tanpa sumbu kapiler yang diletakkan secara vertikal diusulkan sebagai sistem pendingin pasif baru untuk pembuangan panas sisa hasil peluruhan di kolam penyimpanan bahan bakar bekas nuklir. Pipa kalor akan membuang panas peluruhan dari kolam penyimpanan bahan bakar bekas nuklir dan dapat menjaga sistem tetap aman. Tujuan penelitian ini adalah untuk menginvestigasi karakteristik, fenomena perpindahan kalor, dan unjuk kerja termal pipa kalor yang digunakan mencari pengaruh kecepatan pendinginan dengan besarnya kalor yang harus dibuang, menganalisis keserupaan dimensi dari pipa kalor yang digunakan, dan mengetahui teknologi pipa kalor yang dapat digunakan sebagai sistem keselamatan pasif di instalasi nuklir pada kondisi kecelakaan akibat station blackout. Investigasi secara eksperimen dilakukan dengan mempertimbangkan pengaruh tekanan awal pipa kalor, evaporator filling ratio, beban kalor evaporator, dan laju aliran pendingin di water jacket. Air pendingin disirkulasikan dalam water jacket sebagai penyerap kalor di bagian condenser. Simulasi dengan program perhitungan termohidraulika RELAP5/MOD3.2 dilakukan untuk mendukung dan membandingkan dengan hasil eksperimen yang didapatkan. Hasil eksperimen menunjukkan bahwa unjuk kerja termal terbaik pipa kalor didapatkan pada tahanan termal 0,016 C/W. Unjuk kerja termal terbaik didapatkan pada saat pipa kalor diberikan filling ratio 80 , tekanan awal terendah, laju aliran pendingin tertinggi, dan beban kalor evaporator tertinggi. Dari nilai tahanan termal tersebut didapatkan bahwa pipa kalor ini memiliki kemampuan memindahkan kalor 199 kali lebih besar jika dibandingkan dengan batang pejal tembaga dengan geometri yang sama. Model pipa kalor dalam simulasi dengan RELAP5/MOD3.2 dapat digunakan untuk mendukung investigasi secara eksperimen dalam memprediksi fenomena yang berlangung di bagian dalam pipa kalor. Analisis dimensi dan keserupaan pipa kalor yang didapatkan bisa digunakan untuk merancang pipa kalor lain dengan geometri yang berbeda namun tetap menghasilkan unjuk kerja termal yang sama. Kesimpulan investigasi yang dilakukan menunjukkan bahwa pipa kalor ini memiliki unjuk kerja termal yang tinggi dan dapat digunakan sebagai sistem pendingin pasif di kolam penyimpanan bahan bakar bekas nuklir pada saat terjadinya kecelakaan akibat station blackout.

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To enhance the thermal safety when station blackout accident occurs, a vertical straight wickless heat pipe is proposed as a new passive residual heat removal system in nuclear spent fuel storage pool. The heat pipe will remove the decay heat from nuclear spent fuel pool and keep the system safe. The objective of this research is to investigate the characteristics, heat transfer phenomena, and thermal performance of heat pipe, to analyse the effect of coolant flowrate against heat to be removed, analysing the dimensional similarity of heat pipe, and to know the heat pipe technology that could be used as passive safety system in nuclear installation during to station blackout accident. The experimental investigation was conducted to investigate the heat transfer phenomena and heat pipe thermal performance with considering the influence of heat pipe initial pressure, evaporator filling ratio, evaporator heat load, and coolant volumetric flow rate of water jacket. Cooling water was circulated in water jacket as condenser cooling system. A numerical simulation with nuclear reactor thermal hydraulic code RELAP5 MOD3.2 was performed to support and to compare with the experimental results. The experimental results showed that the best thermal performance was obtained at thermal resistance of 0.016 C W, with filling ratio of 80 , the lower initial pressure, higher coolant volumetric flow rate, and higher heat load of evaporator. From thermal resistance analysis, it is found that the heat pipe has the ability to remove heat 199 times greater than copper rod with the same geometry. The RELAP5 MOD3.2 simulation model can be used to support experimental investigation and to predict the phenomena inside the heat pipe. The dimensional analysis and similitude of the heat pipe can be applied to design the other heat pipe with different geometries with produces the same thermal performance. The conclusion of investigation showed that vertical straight wickless heat pipe has higher thermal performance and can be used as passive residual heat removal system of nuclear spent fuel pool when station blackout occurs."